diff --git a/src/tools.c b/src/tools.c
index 3796c98b11b1..5f44a2f0c768 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -5751,11 +5751,12 @@ uint32_t parse_line(char *in, char *out, size_t *outlen, char **args, int *nbarg
 	/* end of output string */
 	EMIT_CHAR(0);
 
-	/* don't add empty arg after trailing spaces. Note that args[arg]
-	 * may contain some distances relative to NULL if <out> was NULL,
-	 * so we test <out> instead of args[arg].
+	/* Don't add an empty arg after trailing spaces. Note that args[arg]
+	 * may contain some distances relative to NULL if <out> was NULL, or
+	 * pointers beyond the end of <out> in case <outlen> is too short, thus
+	 * we must not dereference it.
 	 */
-	if (arg < argsmax && out && *(args[arg]))
+	if (arg < argsmax && args[arg] != out + outpos - 1)
 		arg++;
 
 	if (quote) {